Multiple audio signal recording and reproducing apparatus

ABSTRACT

A recording/reproducing apparatus for recording and reproducing input signals having left and right stereo sounds. The stereo audio components of television signals prior to recording are data compressed and multiplexed. Then the stereo components are recorded in two channels, a left channel and a right channel. In playback, the audio signals are retrieved by the control signal from audio sound tracks of the recording medium.

This application is a division of application Ser. No. 08/156,101, filedNov. 22, 1993, now U.S. Pat. No. 5,594,551.

BACKGROUND OF THE INVENTION

The present invention relates to a method of recording a plurality oftelevision signals of different programs and reproducing a desiredprogram and to an apparatus for the same.

As satellite broadcasting services have expanded using broadcastingsatellites (referred to as BS hereinafter) and communications satellites(referred to as CS), there has been an increase in service programswhich often need multi-channel signal transmission. In a conventionalhome video tape recorder (VTR), one program can usually only be recordedat a time although the VTR can receive two or more programs which aretransmitted on the multiple channels.

A technique of recording two or more programs at a time is known and isillustrated in FIG. 9(a). FIG. 9(a) is a block diagram of the apparatuscapable of recording and reproducing three different audio/video signalsat the same time. As shown, three input terminals 14A, 14B, and 14C areprovided for receiving three different audio/video signals A, B, and Crespectively. The input terminals are coupled to three input signalprocessors 15A, 15B, and 15C which are adapted for time dividing theirrespective audio/video signals A, B, and C into three rows of fields A1,B1, and C1. The input signal processors also produce three first controlsignals α1, β1, and γ1 for specifying the three field components A1, B1,and C1 respectively.

A recording sync signal processor 16 responsive to the first controlsignals α1, β1, and γ1 is provided for producing a second control signalα for determining an order for the three field components A1, B1, and C1and a third control signal β for identifying the three field componentsA1, B1, and C1. A recording signal processor 17 responsive to the secondcontrol signal α is provided for transmitting combinations of the fieldcomponents A1, B1, and C1 grouped in a set of three differentaudio/video signals. A recorder unit 18 is provided for recording thefield components A1, B1, and C1 and the third control signal β in agiven format on a magnetic recording tape as shown in FIG. 9(b).

During reproduction, a reproducing sync signal processor 21 responsiveto the third control signal β, which has been reproduced and fed fromthe recorder unit 18, is provided for producing a fourth control signalΔ. This signal identifies the field components A1, B1, and C1 to bereproduced at the recorder unit 18. A reproduced signal processor 19responsive to the fourth control signal Δ is provided for allocating thereproduced field components A1, B1, and C1 supplied from the recordingunit 18 to three discrete channels. The reproduced field components A1,B1, and C1 of the audio/video signals are then transmitted along theirchannels to three output signal processors 20A, 20B, and 20C,respectively. At this point the field components of each audio/videosignal are joined one to the other. A switch 22 is provided forselecting one of the three produced audio/video signals and outputtingthe selected reproduced audio/video signal to an output terminal 23.

In operation, the three different audio/video signals A, B, and C aretime divided by their respective input signal processors 15A, 15B, and15C into field components. Simultaneously, three of the first controlsignals a1, β1, and γ1 are produced for specifying their respectivefield components A1, B1, and C1 of the audio/video signals.

The three field components A1, B1, and C1 are transmitted to therecording signal processor 17 while the three first control signals α1,β1, and γ1 are fed to the recording sync signal processor 16. Inresponse, the second control signal α is sent from the recording syncsignal processor 16 to the recording signal processor 17 for determininga desired order of the three field components A1, B1, and C1.

The recording synch signal processor 16 also produces the third controlsignal β which identifies the field components A1, B1, or C1 andallocates the third control signal β to a pertinent recording track of amagnetic recording tape for storage.

Then, the recording signal processor 17 transmits the field componentsA1, B1, and C1 to the recorder unit 18 in the order determined by thesecond control signal α. In the recorder unit 18, the three fieldcomponents A1, B1, and C1, for example, are recorded in this order intothree adjacent recording tracks 26A, 26B, and 26C of the magneticrecording tape 24 as shown in FIG. 9(b). Simultaneously, the thirdcontrol signal β is stored in a control track 25 for use in the playbackoperation.

During reproduction, the field components A1, B1, and C1 of thereproduced audio/video signals are sent in the same order from therecorder unit 18 to the reproduced signal processor 19. Concurrently,the third control signal β is retrieved and fed to the reproducing syncsignal processor 21. In response to the third control signal β, thereproducing sync signal processor 21 produces the fourth control signalΔ to identify the combination of the three field components A1, B1, andC1 in synchronism. The fourth control signal Δ then causes. thereproduced signal processor 19 to distribute the field components A1,B1, and C1 to their respective channels coupled to the output signalprocessors 20a, 20B, and 20C respectively. As the three channels areturned on by the switch 22, a desired audio/video signal of thereproduction will be obtained.

However, the recording/reproducing apparatus performs a decimation ofdata in both the audio and video components of the signal at an equalrate, thus causing dropoffs in the reproduced sounds. Additionally, itscircuitry arrangement is relatively bulky in size and will most likelycost higher. When a single program has been recorded by themulti-program recording/reproducing apparatus, it is difficult toreproduce the signal in the same quality as of other single programrecording/reproducing apparatuses.

SUMMARY OF THE INVENTION

The present invention provides an improved recording/reproducing methodand a corresponding apparatus for recording and reproducing a pluralityof different television signals. The televisions include videocomponents and audio components.

The recording/reproducing apparatus's circuitry is minimized, therefore,reducing the cost of reproducing the apparatus.

In playback mode, the recorded information to be reproduced isautomatically examined to determine if it contains a single program ormultiple program data so that unwanted deterioration can be avoided inthe playback quality of the single program data.

The recording/reproducing method of the present invention comprises thesteps of selecting and delivering the video components of inputtelevision signals. Then a control signal is extracted from each of theselected video component signals and examined to determine whether theselected video signal is to be recorded or played back. The selectedvideo signal is recorded in a specific pattern on the applicablerecording tracks of a recording medium as defined by the control signal.The above steps are performed for recording the video components of theinput television signals.

Reproduction of the video signals stored on the recording medium isinitiated by selectively retrieving the video signal from the recordingtracks of the recording medium in accordance with its control signal.The reproduced video signals are examined to extract their controlsignals and to enable play back according to their respective controlsignals. The above steps are completed for reconstruction of the videocomponents of the input television signals.

When the input television signals are being recorded, the audio orstereo components of the input television signals are separated. Theright sounds of the stereo components are data compressed andmultiplexed and the left sounds are data compressed and multiplexed.Then, the left and right data compressed and multiplexed signals arerecorded onto the stereo or left/right sound tracks of the recordingmedium respectively.

The audio signals are reproduced by the selective retrieval of audiodata from the audio sound tracks of the recording medium in accordancewith its control signal.

The method of recording and reproducing multiple television signals inaccordance with the present invention consists of processing video andaudio components separately in both the recording and playback modes.Accordingly, when a plurality of different television signals areprovided, both the video and audio components of each television signalcan be recorded. Reproduction of a desired television signal can beensured by reconstructing its video and audio components separately. Oneadvantage of the present invention is that the audio signal is datacompressed prior to recording and also, that a control signal is used,e.g. a sync signal and/or an extra signal attributed to the originaltelevision signal for use in both the recording and playback modes.

When the data input contains two different television signals, the stepsof recording and reproducing the audio components are executedseparately. Specifically, recording is implemented by receiving twoaudio stereo signals corresponding to the respective television signals.Then recording one channel of one of the two signals, the first audiosignal, onto either the right or left sound track of the recordingmedium while one channel of the other, the second audio stereo signal,is recorded onto another sound track. The second audio signal is notrecorded on the same channel as the first audio sound signal. Inplayback, the audio stereo sound signals are reproduced from the audiosound tracks of the recording medium using the control signal of thevideo signal.

Accordingly, two audio stereo components can be recorded in monauralmode.

A recording/reproducing apparatus of the present invention employing theforegoing method of recording and reproducing multiple televisionsignals includes a video signal input section for receiving videocomponents of the television signals and selectively delivering thevideo components. A video signal examining section for receiving thevideo output of the video signal input section, extracting a controlsignal from each video component, and determining whether the videosignal is to be recorded or played back. A recording control section isprovided for selecting a specific pattern of applicable recording tracksof a recording medium in response to the control signal and recordingthe video signals, which are to be recorded in accordance with itscontrol signal, onto the designated recording tracks. A playback controlsection is provided for reproducing the video signal from the recordingtracks of the recording medium in a sequence defined by the controlsignal. An audio signal recording/reproducing section receives thestereo audio signals which match their respective video signals. Theright sounds of the stereo audio signals are data compressed andmultiplexed, and the left sounds of the stereo audio signals are datacompressed and multiplexed. Both the right and left data compressed andmultiplexed audio signals are recorded onto corresponding right and leftstereo sound tracks of the recording medium. The audio signalrecording/reproducing section also selectively reproduces desiredsignals from the stereo sound tracks of the recording medium inaccordance with the control signal of the television signal to be playedback. The output of the playback control section is coupled to the inputof the video signal input section.

Accordingly, the video and audio components of the multiple televisionsignals can be recorded and reproduced. Both the video signal to berecorded and the reproduced video signal are fed and processed in thevideo signal input section. Any playback signal as well as any inputsignal are examined to detect a control signal of the video input.Hence, the selection between recording and reproducing and other signalprocessing is determined by analyzing the control signal in the samecircuit. This arrangement minimizes the size of the apparatus.

In addition, the recording control section is adapted to display on adisplay at least one of the multiple video signals to be recorded andalso, to selectively indicate on the display at least one of theplayback video signals reproduced by the playback control section. Thisallows another circuit to be developed for recording and reproducing.

Furthermore, the playback control section has a playback mode controlterminal for feeding an external control signal so that recorded datacan be reproduced directly from the recording tracks of the recordingmedium. When the recorded data is a single program television signal, itcan be reproduced directly from the recording tracks without performingany sampling action. As a result, deterioration in the playback qualityof the single program television signal may be minimized. Themulti-program television signal consists of even or odd fields as isconstructed by a given sampling technique. Therefore, a single programtelevision signal can easily be identified by detecting its signalformat of alternate even and odd fields. As the single programtelevision signal is identified, it is directly reproduced from therecording medium without sampling. This will help prevent undesiredquality deterioration in the playback.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1(a) and 1(b) are flow charts of steps of a recording andreproducing method showing a first embodiment of the present invention;

FIGS. 1(c) and 1(d) are flow charts of steps of another recording andreproducing method showing a fourth embodiment of the present invention;

FIG. 2(a) is a block diagram of a video signal recording/reproducingapparatus showing a second embodiment of the present invention;

FIG. 2(b) is a block diagram of another video signalrecording/reproducing apparatus according to the fourth embodiment;

FIG. 3(a) is a block diagram of a further video signalrecording/reproducing apparatus showing a third embodiment of thepresent invention;

FIG. 3(b) is a block diagram of the video signal recording/reproducingapparatus of the fourth embodiment;

FIG. 4 is a block diagram of an audio signal recording/reproducingapparatus showing a fifth embodiment of the present invention;

FIG. 5 is a block diagram of another audio signal recording/reproducingapparatus showing a sixth embodiment of the present invention;

FIG. 6 is a block diagram of a multiplexing and recording section in thefifth embodiment;

FIG. 7(a)-7(b) are explanatory view showing format patterns of themultiple video signals;

FIGS. 8(a)-8(b) explanatory view showing format patterns of the multipleaudio signals; and

FIG. 9(a)-9(b) are block diagram of a prior art recording/reproducingapparatus.

DETAILED DESCRIPTION OF THE INVENTION

First Exemplary Embodiment

A multiple television signal recording/reproducing method according tothe first exemplary embodiment of the present invention and itsapparatus will be described referring to the accompanying drawings.FIGS. 1(a) and 1(b) illustrate using flow charts the recording andreproducing method.

As shown in FIG. 1(a), a plurality of television signals of differentformats, e.g. BS or CS signals, are received and then examined in Step(a) so that a television signal can be selected to meet the purpose. Oneselected television signal is transferred to Step (b) where a controlsignal from the television signal is detected, extracted, and examined.At step (b) it is determined whether the control signal is a sync signalattributed to the television signal or an extra data signal indicatingthe television signal character, e.g., a playback signal or a recordingsignal (in this exemplary embodiment, the control signal is examined todetermine whether it is to be recorded or not).

When the selected television signal has been identified as a televisionsignal to be recorded at Step (b), its video and audio components areseparated. The video components are allocated by the control signal tocorresponding recording tracks of a recording medium for separatestorage at Step (c). At Step (d), the audio components are extracted,data compressed, multiplexed, and recorded in accordance with thecontrol signal onto the audio sound tracks of the recording medium.Steps (c) and (d) are performed substantially at the same time. Step (d)can occur prior to step (c). If the selected television signal is foundto be a signal which is not to be recorded at Step (b), it will simplybe played back on a display at step (e).

The television signals recorded in the recording medium by the foregoingmethod are reproduced by retrieving the television signals directly fromthe recording medium at Step (f) as shown in FIG. 1(b). The reproducedtelevision signals are then transferred to Step (g) where they and otherinput television signals are examined for selection. The selectedtelevision signal is examined at Step (h) to determine whether it is tobe played back or recorded. If it is determined that the selectedtelevision signal is to be played back, the selected television signalis processed at Step (i) by reversing the recording method as defined bythe control signal. Specifically, the selected television signal's videocomponents are reconstructed by combining the video signal data, whileselected television signal's audio components are demultiplexed and dataexpanded. Combining of the video signals is the inverse of the signaldata separation. The reproduced television signal is then displayed atStep (j). Accordingly, multiple television signals can be retrieved fromthe recording medium and played back as desired. If the selectedtelevision signal is determined to be another input television signal atstep (h), the procedure moves to the recording procedure shown in FIG.1(a).

Second Exemplary Embodiment

FIG. 2 is a block diagram of a second exemplary embodiment of therecording/reproducing apparatus for recording and reproducing videocomponents of an input television signal.

Video signal input terminals 1 and 2 are provided for receiving thevideo components of input television signals. A video selector switch 3is provided for selecting the input video signals to pass. A controlpulse generator 6 is provided for detecting a control signal from theselected video signal and for producing a control pulse signal accordingto the control signal. The recording/reproducing selector switches 4 and9 switch the input in response to the control pulse signal of thecontrol pulse generator 6. The control pulse signal indicates whetherthe selected video signal is to be recorded or simply played back. Thesignal processor 5 is provided for processing the selected video signaloutput of the recording/reproducing selector switch 4 according to thecontrol pulse signal from the control pulse generator 6.

A recording switch 7 transmits the video signal processed by the signalprocessor 5 and its corresponding control pulse signal from the controlpulse generator 6 to a recorder unit 8 which records the video signalfrom the recording switch 7 in response to its control signal.

A playback mode input terminal 12 is provided for selectivelycontrolling the playback mode to reproduce the video signal stored inthe recorder unit 8. Video signal output terminal 10 outputs the videosignal released by the recording/reproducing selector switch 9 forplayback.

The operation of the recording/reproducing apparatus of the secondembodiment is explained below using two video signals for simplicity.

The two video signals A and B are received at input terminals 1 and 2,respectively. The video signals are transmitted to the video signalselector switch 3 where, for example, video signal A is selected forrecording in response to the control or selecting pulse signal from thecontrol pulse generator 6. The two video signal input terminals 1 and 2and the video signal selector switch 3 are the video signal inputsection. In response to the control or recording/reproducing selectingpulse signal from the control pulse generator 6, therecording/reproducing selector switch 4 selects video signal B, forexample, to be combined with video signal A for recording. Therecording/reproducing selector switch 4 and the control pulse generator6 are the video signal examining section. The video signal B deliveredfrom the recording/reproducing selector switch 4 is fed to the signalprocessor 5 where it is synchronized in field or frame with the videosignal A according to the signal processing control pulse signal fromthe control pulse generator 6. The field or frame synchronization may beimplemented using field or frame memories. The synchronized videosignals A and B are transmitted to the recording switch 7 where they arecombined together by the recording mode control pulse signal from thecontrol pulse generator 6. The combined video signal is then deliveredto the recorder unit 8. The signal processor 5, the recording switch 7,and the recorder unit 8 constitute a recording control section.

This sequence of actions is described below in more detail withreference to the format patterns of the signals. As shown in FIG. 7(a),the video signal A consists of a series of fields A1, A2, . . . whilethe video signal B consists of B1, B2, . . . As the two signals are fedto the video signal input terminals 1 and 2, video signal A is selectedby video signal selector switch 3 because it is regarded as a referencesignal for the synchronizing operation. The video signal B is selectedby the recording/reproducing selector switch 4 and fed to the signalprocessor 5. As shown in FIG. 7(a), the output of the signal processor 5is the video signal B synchronized in field with the video signal A.Then in the recording switch 7, as shown in FIG. 7(a), the video signalA and the synchronized video signal B are combined by sampling thefields of the two signals alternatively. The resulting sampled signalfrom the recording switch 7 is then recorded by the recorded unit 8.

The recording/reproducing selector switch 9 allows the video signal A topass to the video signal output terminal 10 according to therecording/reproducing control pulse signal from the control pulsegenerator 6. Hence, the video signal A can be played back on a displaywhile the combined signal is being recorded. When one program is to berecorded, the control pulse generator 6 sends a recording mode controlpulse signal to the recording switch 7. This allows the video signal Ato pass through recording switch 7 without sampling. Therefore videosignal A can be recorded in the same manner as a traditional one-programrecorder.

To retrieve a signal, the video signal selector switch 3 receives aplayback mode control pulse signal from the control pulse generator 6.This selects the output signal of the recorder unit 8 for playback. Theinput video signals from the video signal input terminals 1 and 2 arerejected when the recorder unit 8 is in playback mode. The output signalof the recorder unit 8 is then fed to the recording/reproducing selectorswitch 4 where it is determined whether the signal is to be played backin accordance with the recording/reproducing switching control pulsesignal from the control pulse generator 6. The signal output of therecorder unit 8 is then passed through the circuit which contains thevideo input section and the video signal processing section. Thiscircuit was used to record the video signal initially. The signal outputof the recorder unit 8 is processed by the signal processor 5 which canserve as a playback control unit. The signal processor 5 is triggered bya signal processing control pulse signal from the control pulsegenerator 6 to perform an inversion of the signal combining actionimplemented by the recording switch 7. As a result, either of the videosignals A and B can be reproduced for playback.

Playback of the recorded signals is described with reference to theformat patterns of the signals. As shown in FIG. 7(b), the multi-programsignal recorded by the recorder unit 8 is directly reproduced. Theoutput signal released from the recorder unit 8 is processed by thesignal processor 5 using field or frame memories to reconstruct thevideo signal A or B. For ease of the description, FIG. 7(b) shows areproduced signal, for example, where the dropout in the signal iscompensated with the previous field or frame data. It is understood thatthe compensation of data may be carried out by field or frameinterpolation with equal success.

The control pulse generator 6 also produces a secondrecording/reproducing switching control pulse signal in response to aplayback mode signal fed through the playback mode input terminal 12. Inresponse to the second recording/reproducing switching control pulsesignal from the control pulse generator 6, the recording/reproducingselector switch 9 determines if the reproduced video signal is from asingle program or from a multi-program video signal which containstwo-program data. The recording/reproducing selector also transmits thereproduced video signal to the video signal output terminal 10 forplayback. The determination of whether the reproduced video signal is asingle program video signal or a two-program multiple video signal isperformed to avoid the sampling action which is essential forreproduction of the multi-program video signal but which causes aquality deterioration in the playback of the single program videosignal.

Third Exemplary Embodiment

FIG. 3 is a block diagram of a third exemplary embodiment of therecording/reproducing apparatus for recording and reproducing videosignals.

The apparatus includes two video signal input terminals 1 and 2, a videosignal selector switch 3, two recording/reproducing selector switches 4and 9, a signal processor 5, a control pulse generator 6, a recordingswitch 7, a recorder unit 8, and a video signal output terminal 10.These components are similar to the components of the second embodiment.The third embodiment is distinguished from the second embodiment by theapplication of a playback mode examining unit 13.

The operation of the recording/reproducing apparatus of the thirdexemplary embodiment is explained below. When two video signals A and Bhave been received through their respective video signal input terminals1 and 2, the video signal selector switch 3 selects the video signal A,for example, according to a video signal selecting control pulse signalfrom the control pulse generator 6. The recording/reproducing selectorswitch 4 selects the other video signal B according to arecording/reproducing switching control pulse signal from the controlpulse generator 6. Then, the video signal B is fed to the signalprocessor 5 where it is synchronized with the video signal A by a signalprocessing control pulse signal from the control pulse generator 6. Thefield synchronization is implemented using field memories. The recordingswitch 7 then combines the synchronized video signals A and B, inresponse to a recording mode control pulse signal from the control pulsegenerator 6. The multi-program signal is then delivered to the recorderunit 8.

The above series of steps are identical to the steps of the secondembodiment. The output signal of the recording switch 7 which isrecorded by the recorder unit 8 is shown in FIG. 7(a). The output signalof the recording switch 7 consists of either even or odd fields.

The recording/reproducing selector switch 9 selects the video signal Aaccording to a recording/reproducing switching control pulse signal fromthe control pulse generator 6. While in the recording mode, therecording/reproducing selector switch 9 transmits video signal A throughto the video signal output terminal 10 for playback on a display. Duringthe recording of a single program video signal, the video signal A candirectly be transferred through the recording switch 7 in accordancewith a corresponding recording mode control pulse from the control pulsegenerator 6.

When the video signal is reproduced, the video signal selector switch 3selects the output signal of the recorder unit 8 in response to a videosignal selecting pulse signal from the control pulse generator 6. Theoutput signal of the recorder unit 8 is also selected by therecording/reproducing selector switch 4 in response to arecording/reproducing switching control pulse signal from the controlpulse generator 6. The output signal of the recording unit 8 is then fedto the signal processor 5 where either the video signal A or B isextracted and reconstructed by a signal processing control pulse signalfrom the control pulse generator 6. The reconstruction of the videosignal A or B is similar to that of the second embodiment as shown inFIG. 7(b), in which data from the field memories is utilized forcompensation. FIG. 7(b) shows the compensation of data dropouts usingthe previous field data for ease of explanation. Field interpolation mayalso be used with equal success for maintaining the image quality.

The playback mode examining unit 13 of the third embodiment examines theorder of even and odd fields in the output signal of the video signalselector switch 3. This process is performed on the multi-program videosignal which may consist of either even or odd fields which have beensampled. The video signal of one program consists of alternate odd andeven fields while the multi-program video signal is composed of a seriesof either even or odd fields. The even or odd fields are present only iftwo program signals have been combined to produce a multi-program videosignal for recording. A playback mode signal determined by the playbackmode examining unit 13 is supplied to the control pulse generator 6which in turn generates a corresponding second recording/reproducingswitching control pulse signal. In response to the secondrecording/reproducing switching control pulse signal from the controlpulse generator 6, the recording/reproducing selector switch 9determines whether one or two-program video signals are present.Recording/reproducing selector switch 9 passes the video signal to thevideo signal output terminal 10. A video signal composed of even or oddfields which is substantially similar to the existing nonstandard signalcan be played back by a conventional VTR without difficulty.

Fourth Exemplary Embodiment

FIG. 2(b) is a block diagram of a recording/reproducing apparatus forrecording and reproducing video signals showing a fourth embodiment ofthe present invention. The fourth embodiment is differed from the secondembodiment by the fact that the video selector switch 3 is connected toan external input terminal for receiving an external video selectingcontrol pulse signal similar to the video selecting control pulse fromthe control pulse generator 6 and also, the control pulse generator 6 isconnected to an external input terminal for receiving a recording modesignal. The other arrangement is identical to that of the secondembodiment.

In common, the recording mode is determined by a video signal to berecorded. For multiplex recording of two different video signals forexample, the recording mode is selected so that the two signals arerecorded alternately in fields or frames. For the purpose, the controlpulse generator 6 systematically produces the signal processing controlpulse containing a recording mode data as described in the secondembodiment.

In addition, if the supply of such a control pulse signal is enabledthrough the external input terminal, it can determine which video signalis selected at the video selector switch 3 and which mode is used forrecording the selected video signal. Upon receiving the video signalselecting pulse signal fed through the external input terminal, thevideo selector switch 3 selects a corresponding video signal to pass.Simultaneously, the video signal selecting pulse signal and a relevantrecording mode signal are fed to the control pulse generator 6 which inturn produces a corresponding signal processing control pulse. Theselected video signal is then processed by the signal processor 5according to the signal processing control pulse and fed to the recorder8 for recording.

This series of actions will be explained referring to the flow chart ofFIG. 1(c). As shown, Step b of the first embodiment is divided intothree sub steps: Step b1 where a control signal is detected or infedthrough the external input terminal, Step b2 where in response to thecontrol signal detected or infed, the control pulse generator 6 producesa control pulse signal, and Step b3 where it is determined from thecontrol pulse signal whether the recording or playback operation isexecuted. For processing a reproduced television signal, Step h of thefirst embodiment is divided into three sub steps, as shown in FIG. 1(d):Step h1 where a control signal is detected or infed through the externalinput terminal, Step h2 where in response to the control signal detectedor infed, the control pulse generator 6 produces a control pulse signal,and Step h3 where it is determined from the control pulse signal whetherthe playback or recording operation is executed.

Accordingly, the control on the recorder 8 can favorably be adjusteddepending on the types of recording mediums. Also, a desired recordingmethod optimum to the purpose can be used thus increasing the efficiencyof its operation.

Similarly, a modification of the video signal recording/reproducingapparatus of the third embodiment is shown in the block diagram of FIG.3(b). It is differed from the third embodiment by the fact that thevideo selector switch 3 is connected to an external input terminal forreceiving an external video selecting control pulse signal similar tothe video selecting control pulse from the control pulse generator 6 andalso, the control pulse generator 6 is connected to an external inputterminal for receiving a recording mode signal. The other arrangement isidentical to that of the third embodiment. Accordingly, both theselection of a video signal and the recording mode setting can becontrolled from the outside. More particularly, a desired recording modeappropriate to the type of a recording medium or specified for thepurpose can be determined.

Fifth Embodiment

FIG. 4 is a block diagram of a further recording/reproducing apparatusfor recording and reproducing audio signals showing a fifth embodimentof the present invention.

As shown, there are provided a first right sound input terminal 27, afirst left sound input terminal 28, a second, right sound input terminal29, a recording switch 31, a recorder unit 32, two output switches 34and 35, a right sound output terminal 36, and a left sound outputterminal 37.

The action of the apparatus of the fourth embodiment will be describedwith the application of two different television signals. In recordingaudio components of the two television signals, the right sound of anaudio component of one or first television signal is fed through thefirst right sound input terminal 27 to the right sound input of therecorder unit 32. Simultaneously, the recording switch 31 upon detectingthe feeding of the right sound of an audio component of the other orsecond television signal to the second right sound input terminal 29transmits the right sound to the left sound input of the recorder unit32. In other words, the right sounds of stereo audio components of thetwo television signals are recorded in monaural mode on audio soundtracks of the recording medium.

When one television signal is involved, its stereo audio components arefed the right sound through the first right sound input terminal 27 tothe right sound input of the recorder unit 32 and the left sound throughthe first left sound input terminal 28 and the recording switch 31 tothe left sound input of the same. More specifically, the stereo soundsof the single television signal are supplied at a time to the firstright and left sound input terminals 27, 28 respectively and then,recorded in a stereo mode as compared with the monaural mode of thefirst and second right sounds resulting from the supply to the secondright sound input terminal 29. The two sounds fed to the first right andleft sound input terminals 27, 28 are also transmitted to theirrespective output switches 34 and 35 where they are admitted and allowedto run to the right and left sound output terminals 36 and 37respectively for monitor use.

In playback, the two different sound data are released from the left andright sound outputs of the recorder unit 32 and fed to their respectiveoutput switches 35 and 34. The output switches 34 and 35 selectcorresponding audio components according to a control signal (not shown)detected during reproduction of the video signal and transmit them tothe right 36 and left sound output terminals 37 for further delivery. Ina single stereo sound mode, the two, left and right, sounds releasedfrom the left and right outputs of the recorder unit 32 are directlytransmitted via their respective output switches 35 and 34 up to theleft 36 and right sound output terminals 37.

Sixth Embodiment

FIG. 5 is a block diagram of a still further recording/reproducingapparatus for recording and reproducing audio signals showing a sixthembodiment of the present invention.

As shown, there are provided a first right sound input terminal 27, afirst left sound input terminal 28, a second right sound input terminal29, a second left sound input terminal 30, two multiplexers 38 and 39, arecorder unit 32, two demultiplexers 40 and 41, two output switches 34and 35, a right sound output terminal 36, and a left sound outputterminal 37.

The operation of the apparatus of the sixth exemplary embodiment isdescribed below. When recording two audio signals, first and secondaudio signals, the right sounds of the first and second audio signalsare fed through their respective right sound input terminals 27 and 29to the multiplexer 38 where they are time multiplexed through datacompression. The multiplexed signals are sent to the right sound inputof the recorder unit 32 for storage in audio sound tracks of a recordingmedium. Similarly, the left sounds of the first and second audio signalsare supplied through their respective left sound input terminals 28 and30 to the multiplexer 39 where they are also time multiplexed throughdata compression. The multiplexed signals are sent to the left soundinput of the recorder unit 32 for storage. Accordingly, the left andright channels of multiple stereo audio signals can simultaneously berecorded by multiplexing their data.

When a single stereo sound is to be recorded, its right sound is fedthrough the first right sound input terminal 27 to the right sound inputof the recorder unit 32 without the multiplexing action of themultiplexer 38. Its left sound is supplied through the first left soundinput terminal 28 to the left sound input of the recorder unit 32without the multiplexing action of the multiplexer 39. This function maybe implemented by determining if a signal is being fed to the secondinput terminals 29 and 30. If a signal is not detected, then thefunction of both the multiplexers 38 and 39 can be cancelled. Thisfunction may also be carried out using a control signal detected in thereproduction of the television signal.

During the recording operation, the right and left sounds of the firstaudio signal can also be fed through their respective audio sound inputterminals 27 and 28 to the two output switches 34 and 35. The outputswitches 34 and 35 in turn pass the two sounds to the right and leftsound output terminals 36 and 37, respectively, for monitor use.

When the different program sounds are reproduced, the multiplexed rightsound signal is sent from the right sound output of the recorder unit 32and input into the demultiplexer 40. The right sound output isdemultiplexed by an inversion of the time compression to produce tworight sounds which are then transmitted to the output switch 34.Similarly, the multiplexed left sound signal is sent from the left soundoutput of the recorder unit 32 and input into the other demultiplexer 41where it is demultiplexed by an inversion of the time compression toproduce two left sounds which are then transmitted to the output switch35. The output switches 34 and 35 select the pair of the right and leftsounds according to a control pulse signal extracted during thereproduction of the video component of the input signal. The selectedright and left sounds which match the video signal are sent to theirrespective output terminals 36 and 37. When a stereo sound is played,its right and left sounds which have not been multiplexed aretransferred from the right and left outputs of the recorder unit 32 totheir respective output switches 34 and 35 directly without the need ofdemultiplexing at the demultiplexers 40 and 41. The right and leftsounds are further delivered through the right and left sound outputterminals 36 and 37 respectively.

FIG. 6 shows a modification of the circuitry arrangement of the sixthexemplary embodiment which is substantially equivalent in function tothe combination of the two multiplexers 38 and 39 and the twodemultiplexers 40 and 41. The modified circuit can serve as both amultiplexer unit and a demultiplexer unit. As shown in FIG. 6, thecircuit includes a first multiplex/demultiplex audio input terminal 44,a second multiplex/demultiplex audio input terminal 45, two A/Dconverters 46 and 47, a multiplex/demultiplex selector switch 48, fourmemories 49, 50, 51, and 52, three multiplexing switches 54, 55, and 56,a control pulse generator 53, two D/A converters 57 and 58, a firstmultiplex/demultiplex audio output terminal 59, and a secondmultiplex/demultiplex audio output terminal 60. The operation of thecircuit of FIG. 6 will be explained below with reference to FIGS. 8(a)and 8(b).

A first audio signal AL and a second audio signal BL are input intotheir respective input terminals 44 and 45 and converted from analog todigital by the two A/D converters 46 and 47, respectively. The firstaudio signal AL is velocity converted by the two memories 49 and 50 asshown in FIG. 8. The multiplex/demultiplex switch 48 allows the secondaudio signal BL of digital form to move from the A/D converter 47 to thetwo memories 51 and 52 where it is also velocity converted in a similarmanner. The two velocity converted audio signals A1 and BL aremultiplexed by the combination of the multiplexing switches 54, 55, and56. The resultant multiplexed signal is then converted fromdigital-to-analog by the D/A converter 57. The multiplexed signal isthen transmitted through the first multiplex/demultiplex audio outputterminal 59 to a recorder unit for recording.

During the demultiplexing process, a multiplexed audio signal is fed tothe first multiplex/demultiplex audio input terminal 44 whichdistributes the signal to the four memories 49, 50, 51, and 52. Themultiplex/demultiplex selector switch 48 allows the multiplexed audiosignal to pass. Accordingly, its multiplexed components are velocityconverted by the memories 49, 50, 51, and respectively, to reconstructtwo audio signals AL and BL as shown in FIG. S. The audio signal AL istransmitted through the two multiplexing switches 54 and 56 to the D/Aconverter 57 while the other audio signal BL is sent through themultiplexing switch 55 to the D/A converter 58. The two audio signals A1and BL in analog form are then output to their respective outputterminals 59 and 60 for playback.

As set forth above, the multiple television signal recording/reproducingapparatus of the present invention allows the input television signal tobe divided into two, video and audio, components which are thenprocessed prior to recording and playing back. As a result, the signalcan be recorded or played back without serious deterioration of audioquality. The audio component is recorded in a mono mode or a multiplexmode depending on its format. During playback, the mono signal will bereproduced without developing any audible dropout of sound.

In addition, the video signal is automatically examined to determinewhether or not it is a single program signal or a multiplexed programsignal. This determination is accomplished by reviewing the signalsfield polarity (i.e. detection of even and odd fields). During playback,the single program signal and the multiple program signal aresystematically selected so that deterioration in the playback quality isminimized.

While the invention has been described in terms of the exemplaryembodiments, it is contemplated that it may be practiced as outlinedabove with modifications within the spirit and scope of the appendedclaims.

What is claimed:
 1. A recording/reproducing apparatus for recordinginput signals having left and right stereo sound signals, said apparatuscomprising:a first right sound signal input terminal and a first leftsound signal input terminal for receiving a first stereo sound signal; asecond right sound signal input terminal for receiving a second stereosound signal; a recording switch connected to said first left soundsignal input terminal and said second right sound signal input terminalfor passing and outputting an input signal from said second right soundsignal input terminal when two of said input signals are to be recordedand for passing and outputting an input signal from said first leftsound signal input terminal when one of said first input signals is tobe recorded; recorder means connected to said output of said recordingswitch and to said first right sound signal input terminal for recordingthe stereo sound signals, said recorder means having a right soundsignal output and a left sound signal output; left sound signal outputmeans connected to said first left sound signal input terminal and saidoutput of said recorder means for passing and outputting an input signalfrom said first left sound signal input terminal in the recording modeand for passing and outputting an output signal of said recorder meansin the playback mode; right sound signal output means connected to saidfirst right sound signal input terminal and said signal output of saidrecorder means for passing and outputting in the recording mode an inputsignal from said first right sound signal input terminal and in playbackmode for passing an output signal of said signal output of said recordermeans; a left sound signal output terminal connected to said output ofsaid left sound signal output means; and a right sound signal outputterminal connected to said output of said right sound signal outputmeans.
 2. A recording/reproducing apparatus for recording input signalshaving left and right stereo sound signals, said apparatus comprising:afirst right sound signal input terminal and a first left sound signalinput terminal for receiving a first stereo sound; a second right soundsignal input terminal and a second left sound signal input terminal forreceiving a second stereo sound; first audio signal multiplexer meansconnected to said first and second right sound signal input terminalsfor time compressing, multiplexing and outputting two output signals ofsaid first and second right sound signal input terminals when two inputsignals are to be recorded and for passing and outputting an outputsignal of said first right sound signal input terminal when one inputsignal is to be recorded; second audio signal multiplexer meansconnected to said first and second left sound signal input terminals fortime compressing, multiplexing and outputting two output signals of saidfirst and second left sound signal input terminals when two inputsignals are to be recorded and for passing and outputting an outputsignal of said first left sound signal input terminal when one inputsignal is to be recorded; recorder means connected to said output ofsaid first audio signal multiplexer and said output of the second audiosignal multiplexer for recording said output signals, said recordermeans having a right sound signal output and a left sound signal output;first audio signal demultiplexer means connected to said left soundsignal output of said recorder means for passing and outputting anoutput of said left sound output of said recorder means when one of saidinput signals has been recorded, and demultiplexing and time expandingan output signal of said multiplexed signals from said left sound signaloutput of said recorder means when two of said input signals have beenrecorded; second audio signal demultiplexer means connected to saidright sound signal output of said recorder means for passing andoutputting an output of said right sound output of said recorder meanswhen one of said input signals has been recorded, and demultiplexing andtime expanding an output signal of said multiplexed signals from saidright sound signal output of said recorder means when two of said inputsignals have been recorded; left sound signal output means connected tosaid first left sound signal input terminal and said outputs of saidfirst audio signal demultiplexer for passing and outputting in therecording mode an output signal of said first left sound signal inputterminal and in the playback mode passing one of said two output signalsof said first audio signal demultiplexer; right sound signal outputmeans connected to said first right sound signal input terminal and saidoutputs of said second audio signal demultiplexer for passing andoutputting in the recording mode an output signal of said first rightsound signal input terminal and in the playback mode passing one of saidtwo output signals of said second audio signal demultiplexer; a leftsound signal output terminal connected to said output of said left soundsignal output means; and a right sound signal output terminal connectedto said output of said right sound signal output means.